title: [Microbial regulation of biological characteristics of bacteria in human gut microsymbiocenosis].
abstract: OBJECTIVE
  To study mutual effects of bifidobacteria and opportunistic microorganisms (OM) on their antagonistic, antilysozyme activity and ability to form biofilms.
  
  
  METHODS
  Experiments were conducted on 18 cultures of bifidobacteria and 36 strains of OM isolated from patients during examination on dysbiosis and identified by conventional methods. Exometabolites and cell wall extracts of microorganisms were obtained and used as acting components. Antilysozyme (ALA) and antagonistic activities (AA) as well as formation of biofilms (BF) were studied with biometric method (Bukharin O.V., 1999, 2000; O'Toole G., 2000). Results were statistically handled using Mann-Whitney criterion.
  
  
  RESULTS
  Colonization resistance of gut biotope is determined by features of intermicrobial interactions between dominant and associates revealed in the study: mutual enhancement of ALA and biofilm formation in bifidobacteria and representatives of autochthonic microflora as well as decrease of ALA, BF, and stimulation of AA in Bifidobacterium spp. against allochthonic bacteria and fungi.
  
  
  CONCLUSIONS
  Nature of interactions of bacterial symbionts dominant-associate was determined, which reveal one of the mechanisms of generation of associative symbiosis in human gut biotope.
authors.forename: N B
authors.initials: NB
authors.lastname: Perunova
authors.forename: E V
authors.initials: EV
authors.lastname: Ivanova
authors.forename: O V
authors.initials: OV
authors.lastname: Bukharin
mesh_terms: D000898:Antibiosis; D001644:Bifidobacterium / Q000378:metabolism / Q000502:physiology*; D018441:Biofilms; D002176:Candida albicans / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology; D003106:Colon / Q000382:microbiology*; D004926:Escherichia coli / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology; D006801:Humans; D007711:Klebsiella pneumoniae / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology; D009113:Muramidase / Q000037:antagonists & inhibitors; D013211:Staphylococcus aureus / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology; D013559:Symbiosis
chemical_list: D009113:Muramidase